Snap-action electric toggle switch



April 13, 1965 G. R. LAWSON SNAP-ACTION ELECTRIC TOGGLE SWITCH 2 Sheets-Sheet 1 Filed May 9, 1963 FIGI INVENTOR.

GUSTAF Rv LAWSON Mum/@1464 FIGS KHIIIIIIINU! I g z'l FIGZ ATTORNEY April 13, 1965 G. R. LAWSON SNAP-ACTION ELECTRIC TOGGLE SWITCH 2 Sheets-Sheet 2 Filed May 9, 1963 FIG. 4

INVENTOR GUSTAF R. LAWSON BY 64AM ,mem

ATTORNEY United States Patent 3,178,530 SNAP-ACTION ELECTRKC TGGGLE SWITCH Gustaf Rudolph Lawson, Plainview, N.Y., assignor to General Electric Company, a corporation of New York Filed May 9, 1963, Ser. No. 279,277 10 Claims. (Cl. 200-67) This invention relates to electric switches and more particularly, to electric switches of the toggle variety.

Electric switches of the toggle variety have been commonly used for many years. These switches are particularly advantageous because the toggle mechanism has an inherent snap action which aids in making and breaking the switch contacts quickly, thus reducing arcing and resultant damage to the switch contacts. Quite often this toggle action is achieved through the use of an overcenter spring which cooperates with a pivoted trigger to yield a toggle action.

Prior art toggle switches have been provided with an overcenter coil spring, usually under tension, for this purpose. This construction necessitates the use of at least three separate members; namely, the spring and anchor means for each end thereof. This construction provides a relatively noisy operation, is subject to substantial wear, and is relatively high in cost.

It is an object of this invention to provide an electric switch of the toggle variety wherein the toggle mechanism requires a minimum of parts.

It is a further object of this invention to provide an electric switch of the toggle variety which is simple, reliable and easily and economically manufactured.

It is a still further object of my invention to provide an electric switch of the toggle variety which is quiet in operation.

Briefly stated, in accordance with one form of this invention, the switch actuating member or trigger is provided with a recess in its inner end. Toggle action is provided by a wire spring of somewhat hairpin shape having its bight portion received within the recess in the end of the trigger. The ends of the spring are mounted in the switch housing and provide a resilient force urging the bight portion of the spring into engagement with the walls of the recess.

Further objects and advantages of this invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims and forming part of this specification.

For a better understanding of this invention reference may be had to the accompanying drawings in which:

FIG. 1 is a sectional side view of the toggle switch of this invention taken along the line 1-1 of FIG. 3.

FIG. 2 is a sectional side view of the toggle switch taken along the line 2-2 of FIG. 3.

FIG. 3 is a transverse sectional view of the toggle switch shown in FIGS. 1 and 2, with portions broken away for clarity.

FIG. 4 is an exploded view illustrating the structure of the switch, with some elements omitted for clarity.

FIG. 5 is a perspective view of a modified form of spring employed in the toggle switch of this invention.

Referring now to the drawings, there is shown a toggle switch having a housing 1 which includes a receptacle 2 and a backplate or cover 3 to enclose and protect the operative elements of the switch. In order to mount the housing a mounting plate 4 is secured to the front face of the housing 1. The mounting plate may be anchored to a wall in any suitable manner well known in the art. The housing is secured to the mounting plate by bolts 5, as shown in FIG. 2. These bolts 5 also serve to hold the backplate or cover 3 to the receptacle 2 of the housing.

3,178,539 Patented Apr. 13, 1965 ice The switch includes a fixed contact 6 and a movable contact 7. The fixed contact is secured to or made integral with a terminal Shaving a terminal screw 9 for holding a conductor thereto. T e movable contact 7 is mounted on an elongated contact arm 10. The opposite end of the arm 16 is secured to or made integral with a terminal 11 having a terminal screw 12 for holding a second conductor in engagement therewith.

In order to actuate the movable arm 10 for opening and closing the switch a trigger 13 is provided. Trigger 13 includes a handle portion 14 projecting through an opening 15 in the housing to provide for actuation of the switch. The trigger further includes a second portion 16 received within the housing 1. For pivotally mounting the trigger within the housing oppositely facing projections or shafts 17 are provided on the trigger between the ends thereof. These shafts pivotally support the trigger on semi-cylindrical bearing surfaces 13 positioned on the receptacle 2 at opposite sides of the opening 15. For restraining lateral movement of the trigger 13 U-shaped members, one of which is shown at 19, are provided on the walls of the receptacle 2 in line with the bearing surfaces 18. The ends of the shafts 17 are received within the Ll-shaped members.

For actuating the switch, cam surfaces 21B and 21 are provided on the shafts 17. in the particular form illustrated one of these cam surfaces, specifically the cam surface 20, engages the movable contact arm 10 upon movement of: the trigger to the extreme counterclockwise position shown in FIG. 1 for lifting the arm 10 and opening the switch. It will be understood, however, that if desired a corresponding switch structure could be positioned in the left hand side of the housing, as viewed in FIG. 3, and the movable contact arm of such switch structure would be actuated to the open position by engagement of the cam surface 21 with the arm upon move ment of the trigger to its extreme clockwise position, as viewed in FIG. 1.

In order to effect toggling of the trigger 13 to its two extreme stable positions for opening and closing the switch, an overcenter spring 22 is provided. Spring 22 includes a central bight portion 23 and legs 24, extending outwardly in opposite directions from the ends of the bight portion 23. The overcenter spring 22 is rotatably mounted in the housing 1 by means of spaced lugs 25 on the cover 3 providing bearing surfaces for the spring 22. One of the legs 24 is received within each of the lugs 25.

For receiving the bight portion 23 of the overcenter spring 22 to effect toggle action the inner portion 16 of the trigger 13 is'provided at its end with a recess 26. The recess 26 is formed with oppositely disposed side walls 27 and 28 which are inclined with respect to each other to provide a flared shape of the recess 26. The bight portion 23 of the overcenter spring 22 engages one or the other of the side walls 27 and 23 in the two stable positions of the toggle switch. For example, as shown in FIGS. 1 and 2 when the trigger is in its extreme counterclockwise position effecting opening of the switch, the bight portion of the spring is in engagement with the wall 27. This limits the movement of the trigger in that direction and also damps any vibration at the spring, providing for quiet operation. Conversely, when the trigger is moved to its extreme clockwise position to close the switch the bight portion of the spring 22 engages the inclined side wall 23, similarly limiting movement of the trigger and damping any vibration of the spring.

When the cover 3 is assembled to complete the hous ing 1, pressure is exerted on the legs 24 of the overcenter spring causing the bight portion of the spring to be urged into engagement with the recess 26 with a resilient force. This causes the spring 22 to provide the stored energy for effecting a snap action movement of the switch as the trigger is moved overcenter in either direction. It can be seen, therefore, that the utilization of a simple spring member which may be easily formed from suitable rod or wire stock provides an effective, economical and quiet toggle action.

In order to prevent any possibility of the overcenter spring 22 being urged by its resilience out of engagement with the recess in either of the two extreme positions of the switch, a pair of ears 29 and 39 are provided extending inwardly from the side walls 27 and 28 respectively of the recess. These ears face each other and are generally centrally positioned within the recess so that one or the other of the ears projects within the bight portion 23 of the overcenter spring in each of the two extreme stable positions of the switch. The ears are generally triangular in cross-section so that, combined with the inclined shape of the side walls 27 and 28, the facing edges 31 and 32 of the ears are generally parallel to provide therebetween a slot 33 whose width is substantially equal to the diameter of the wire of which the spring 22 is made. It can be seen, particularly by reference to FIG. 2, that the interposition of the cars 29 and prevents any resilient force stored in the overcenter spring 22 from urging the bight portion 23 out of the recess along one or the other of the inclined side walls in either of the extreme positions of the trigger.

To prevent any possibility of damage to the overcenter spring 23 and movable contact 10, by excessive inward movement, and also to insure against any possibility of inadvertent access to electrical components within the housing through inward movement of the trigger, stop bosses or members 34 are provided on the cover 3 of the housing. As best shown in FIGS. 1 and 2 the stop bosses are normally slightly spaced from the inner edges the small space between the inner end of the trigger and the stop bosses 34. Further inward movement of the trigger is blocked by engagement of the stop bosses with the edges 35 and 36 of the trigger.

The operation of the toggle switch is as follows. Assuming the switch is in the off position shown in FIG. 1, if it is desired to move the switch to its on position, the trigger 13 is moved by the handle 14 in a clockwise direction. As the trigger moves toward its central position, the distance between the bottom of the recess 26 and the rotational axis of the overcenter spring decreases. As a result a compressive force is exerted on the spring 22 and energy is stored in the spring. As the trigger moves past its mid-position, the spring tends to return to its original form because of the stored energy and thereby causes rapid movement of the trigger to its other extreme position, closing the switch. Movement of the trigger in the clockwise direction is limited by engagement of the bight portion 23 of the spring with the side wall 28 of the recess, this engagement damping any vibration of the spring and providing a quieter operation. A similar operation takes place when the trigger is moved back to the position of FIG. 1 to open the switch, the bight portion 23 engaging the side wall 27 of the recess to limit movement of the trigger in that direction and to insure quiet operation of the switch.

A modified form of overcenter spring 37 is shown in FIG. 5. This spring difiers from that shown in the form previously described in that the bight portion 38 is formed as a loop. The ends of the legs 39 and 40 are bent as shown to provide portions 41 and 42 respectively engaging the lugs 25 on the cover 3. The use of the loop shape of the bight shown in FIG. 5 reduces the possibility of rubbing of the spring on the walls of the recess 26 adjacent the edges 35 and 36 of the trigger 13. This assists in insuring ease of operation and minimizes wear.

Although a specific embodiment of this invention has been shown and described it will be apparent that the invention is not limited to the particular construction shown and described and it is intended by the appended claims to cover all modifications within the spirit and scope of this invention.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. A toggle switch comprising:

(a) a housing having an opening therein,

(1')) a trigger pivotally mounted within said housing, said trigger having a handle portion extending through said opening and a second portion received within said housing, said second portion having a recess therein, and

(c) an overcenter spring having a central bight portion and two legs extending from opposite sides of said central bight portion,

(a') said legs being rotatably mounted in said housing,

(e) said bight portion being received within said recess in stressed engagement therewith, whereby said trigger is urged by said spring to either of two stable positions with a snap action.

2. A toggle switch comprising:

(a) a housing having an opening therein,

(b) said housing having spaced bearing surfaces provided therein on opposite sides of said opening,

(0) a trigger having a handle portion extending through said opening and a second portion received within said housing,

(d) said trigger having oppositely extending projections thereon intermediate its ends, said projections engaging said spaced bearing surfaces to provide pivotal mounting of said trigger in said housing,

(e) said second portion of said trigger having a recess therein, and

(f) an overcenter spring having a central bight portion and two legs extending from opposite sides of said central bight portion,

(g) said legs being rotatably received in said housing,

(h) said bight portion being received within said recess in stressed engagement therewithrwhereby said trigger is urged by said spring to either of two stable positions with a snap action.

3. The toggle switch of claim 2 wherein at least one of said projections includes a cam surface thereon and wherein said switch includes an elongated movable contact arms engageable by said cam surface for actuating said switch.

4. A toggle switch comprising:

(a) a housing having an opening therein,

([1) a trigger pivotally mounted within said housing, said trigger having a handle portion extending through said opening and a second portion received within said housing, said second portion having a recess therein, and

(c) an overcenter spring having a central bight portion and two legs extending from opposite sides of said central bight portion,

(d) said legs being rotatably mounted within said housing,

(2) said bight portion being received within said recess in stressed engagement therewith, whereby said trigger is urged by said spring to either of two stable positions with a snap action,

(f) opposite side walls of said recess being inclined to provide a flared opening, whereby said bight portion engages said one of said side walls at one of said stable positions and the other of said side walls at the other of said stable positions.

5. The toggle switch of claim 4 including an ear extending inwardly from each of said side walls, said ears facing each other and being spaced from each other to receive said overcenter spring therebetween, said ears preventing the resilient force of said spring from causing displacment of said spring from said recess in the stable positions of said switch.

6. The toggle switch of claim 5 wherein each of said ears is triangular in cross-section to provide a slot between said ears whose width is substantially equal to the diameter of said spring.

7. A toggle switch comprising:

(a) a housing having an opening therein,

(b) a trigger pivotally mounted within said housing, said trigger having a handle portion extending through said opening and a second portion received within said housing, said second portion having a recess therein, and

(c) an overcenter spring having a central bight portion and two legs extending from opposite sides of said 5 central bight portion,

3 is urged by said spring to either of two stable positions with a snap action,

(f) said housing having a stop member formed thereon,

(g) said second portion of said trigger being normally spaced from said stop member but engaging said stop member upon inward movement of said trigger to prevent excessive inward movement of said trigger.

8. A toggle switch comprising:

(a) a housing having an opening therein,

([2) a trigger pivotally mounted within said housing, said trigger having a handle portion extending through said opening and a second portion received within said housing, said second portion having a recess therein,

() an overcenter spring having a central bight portion and two legs extending from opposite sides of said central bight portion, and

(d) means on said cover for receiving said legs to provide a rotatable mounting of said spring in said housing,

(e) said bight portion being received within said recess in stressed engagement therewith, whereby said trigger 5 is urged by said spring to either of two stable positions with a snap action.

9. The toggle switch of claim 8 wherein said cover further includes a stop member and wherein said second portion of said trigger is normally spaced from said stop member but engages said stop member upon inward movement of said trigger to prevent excessive inward movement of said trigger.

10. A toggle switch comprising:

(a) a housing having an opening therein,

(b) said housing having spaced bearing surfaces provided therein on opposite sides of said opening,

(c) a trigger mounted within said housing, said trigger having a handle portion extending through said opening and a second portion received within said hous- (d) said trigger having bearing surfaces engaging said bearing surfaces on said housing for pivotally mount- References Cited by the Examiner UNITED STATES PATENTS Re. 23,412 9/51 Hollis 20()67 BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner. 

1. A TOGGLE SWITCH COMPRISING: (A) A HOUSING HAVING AN OPENING THEREIN, (B) A TRIGGER PIVOTALLY MOUNTED WITHIN SAID HOUSING, SAID TRIGGER HAVING A HANDLE PORTION EXTENDING THROUGH SAID OPENING AND A SECOND PORTION RECEIVED WITHIN SAID HOUSING, SAID SECOND PORTION HAVING A RECESS THEREIN, AND (C) AN OVERCENTER SPRING HAVING A CENTRAL BIGHT PORTION AND TWO LEGS EXTENDING FROM OPPOSITE SIDES OF SAID CENTRAL BIGHT PORTION, 